1. Field of the Invention
The present invention relates to a method for preparing a sulfone or sulfoxide compound and a catalyst for use therein.
2. Background of the Invention
Sulfone or sulfoxide compounds are important for the production of chemical products and intermediates thereof.
There have been reported processes of preparing sulfone or sulfoxide compounds by the reaction of hydrogen peroxide with sulfide compounds.
For example, J. Org. Chem., 28, 1140 (1963) discloses a process of preparing 2-phenylsulfonylethanol by the reaction of 2-phenylmercaptoethanol with hydrogen peroxide in the presence of a sodium tungstate. However, said method was not effective for other less reactive sulfide other than 2-phenylmercaptoethanol, which is rather reactive sulfide. There have been also reported (1) a process using a cetylpyridinium tungstophosphoric acid as a catalyst (Chem. Lett., 1 (1994)), (2) a process using a methylirheniumtrioxide catalyst (Bull. Chem. Soc. Jpn., 69, 2955 (1996)), (3) a process using quaternary ammonium hydrogensulfate and phenylphosphonic acid in addition to the sodium tungstate (Tetrahedoron, 57, 2469 (2001)). However, these processes are not always industrially satisfactory in that the first process (1) required complicated operations for preparing the catalyst, the catalyst for the second process (2) is expensive, and the third process (3) required expensive phenylphosphonic acid.